Higher-Order Motion-Compensation for In Vivo Cardiac Diffusion Tensor Imaging in Rats.
Higher-Order Motion-Compensation for In Vivo Cardiac Diffusion Tensor Imaging in Rats.
复制标题
DOI：
10.1109/tmi.2015.2411571
复制
发表时间：
2015-09
影响因子：
10.6
通讯作者：
Hsu EW
中科院分区：
文献类型：
--
作者：
Welsh CL;DiBella EV;Hsu EW
心脏的运动使心脏扩散 MRI 和扩散张量成像 (DTI) 的体内应用变得复杂，特别是在目前无法获得超高性能梯度集的大鼠等小动物中。即使通过例如双极编码脉冲进行速度补偿，可变的镜头间残余运动引起的自旋相位仍然会产生明显的伪影。这项研究提出了扩散编码方案，旨在补偿高阶运动分量，包括加速度和加加速度，同时还具有最小 TE 和高可实现 b 值的理想实用特性。这些方案的有效性在真实跳动的心脏模型上得到了数值验证，并通过大鼠体内心脏扩散 MRI 进行了经验证明。人们发现，对于获得质量和信噪比可接受的扩散加权图像而言，对加速度和较低运动分量的补偿是必要且充分的，这产生了在大鼠中展示的第一个体内心脏 DTI。这些发现表明，对高阶运动（特别是加速度）的补偿可以成为高性能梯度硬件的有效替代解决方案，以改善体内心脏 DTI。
Motion of the heart has complicated in vivo applications of cardiac diffusion MRI and diffusion tensor imaging (DTI), especially in small animals such as rats where ultra-high-performance gradient sets are currently not available. Even with velocity compensation via, for example, bipolar encoding pulses, the variable shot-to-shot residual motion-induced spin phase can still give rise to pronounced artifacts. This study presents diffusion-encoding schemes that are designed to compensate for higher-order motion components, including acceleration and jerk, which also have the desirable practical features of minimal TEs and high achievable b-values. The effectiveness of these schemes was verified numerically on a realistic beating heart phantom, and demonstrated empirically with in vivo cardiac diffusion MRI in rats. Compensation for acceleration, and lower motion components, was found to be both necessary and sufficient for obtaining diffusion-weighted images of acceptable quality and SNR, which yielded the first in vivo cardiac DTI demonstrated in the rat. These findings suggest that compensation for higher order motion, particularly acceleration, can be an effective alternative solution to high-performance gradient hardware for improving in vivo cardiac DTI.